mt76: disable bh in mt76_dma_rx_poll

Fixes potential RCU issues and avoids calling ieee80211_rx_napi with softirq
enabled.
Signed-off-by: Felix Fietkau <nbd@nbd.name>

drivers/net/wireless/mediatek/mt76/dma.c

@@ -538,6 +538,7 @@ mt76_dma_rx_poll(struct napi_struct *napi, int budget)
 	dev = container_of(napi->dev, struct mt76_dev, napi_dev);
 	qid = napi - dev->napi;
 
+	local_bh_disable();
 	rcu_read_lock();
 
 	do {
@@ -547,6 +548,7 @@ mt76_dma_rx_poll(struct napi_struct *napi, int budget)
 	} while (cur && done < budget);
 
 	rcu_read_unlock();
+	local_bh_enable();
 
 	if (done < budget && napi_complete(napi))
 		dev->drv->rx_poll_complete(dev, qid);